Methods of and apparatus for applying a stripe of coating material to an elongated article



Oct. 30, 1956 'r. T. BUNCH 2,768,911

METHODS OF AND APPARATUS FOR APPLYING A STRIPE OF COATING MATERIAL TO AN ELONGATED ARTICLE Filed Feb. 2, 1955 2 Sheets-Sheet l INVENTOR.

T. T. BUNCH By A TTORNEY Oct. 30, 1956 T. T. BUNCH METH OF AND APPARA APPLYING A STRIPE OF' 0 TING MATERIAL A LONGATED ARTICLE Filed Feb. 2, 1955 V 2 Sheets-Sheet 2 laa" FIG. 5

INVENTOR.

T. T. BUNCH A TTORNL'VI METHODS OF AND APPARATUS FOR APPLYING A S'IlRIPiE OF COATING MATERIAL TO AN EIJONGATED'ARTICLE V TillmanI-XBunchnear Ashland, Md.,-assignor to Western 7 Electric Company, Incorporated, -New York, N. Y., a corporation of 'New York ApplicationiF ebruary 2,1955, Serial No. 485,764

Claims. (Cl; 117 -'-212) Thisinvention relates to rnethods of and apparatus for applying a coating'material to. articles, and more particularly 'to' methods of and apparatus for applying helical identification stripes to continuously advancing filamentary articles, suchas insulated electrical conductors.

Some types of communication cables comprise a multiplicity ofindividual-ly insulated electrical conductors, which mustbe provided with indicia for identifying particular individual conductors or spe'cialgroups of conductors therein. One means of identifying the conductorsinvolves the application of a helical stripe of paint of a contrasting color to the exterior surface of the insulation--on--theconductor; The helical stripe'preferably should be applied immediately after the plastic insulation has been applied to the conductor in a conventional extrusion operation, while the plastic insulation is still soft due to the heat of the extrusion operation, so that the striping paint will penetrate the insulation and thereby mark -the insulation permanently. Conventional apparatus, employing inking discs or pen points which contact the exterior surface of the plastic insulation to apply the -heli'cal stripe thereto',-' have been found-unsatisfactory due to the factxthat' -the inking discs and penpoint's' -tend to damage 'or distort the soft insulation.

It is an 'object of this invention 'toprovide'new and improvecl m'ethods of=and apparatus for applying coating material to articles.

Another: object-of thi's inve'ntion is to provide new and improved: methods of and apparatus for applying helicalidentification stripesto'continuou'sly moving filamentary articles.- a

A 'methodillu'strating certain features of the-inven tion may inc-ludethe stepsof moving an article relative" to and in close proximity to the surface -of a "bOdYjiOf liquid coating material, and'producing a swell on said surface: immediately adjacent to the relatively-moving article of such height that the crest thereof contactsthe" article.

Apparatus illustrating certain features of the invention may include means forrholding a body of-liquid coatingmaterial, means for moving'an article relative to and-in close proximity to the surface of said coatingma terial, and means for producing a swell on the surface of saidbody of coating'imaterial immediately adjacent to therelativelymoving article of suflicient height 'to' cause the crest thereof to contact the article.

A complete understanding of the invention may be had from the following detailed description of methods and apparatus forming specific embodiments thereof,

when read in conjunction with the appended drawings,in which: I Fig. l is a sideelevation of apparatus forming one embodiment of the inventiomwith parts thereof 'brok'en away. for. clarity;

Fig.2 is an-enlarged,fragmentary, vertical section" 2 ,768,911 Patented Oct. 30521956 taken along the longitudinal axis of a fluid holder forming-a part of the apparatus shown in Fig. 1;

Fig. 3 is an enlarged, fragmentary, vertical section taken along'line 3-3 of Fig. 2;

Fig. 4 is a fragmentary, vertical section taken along line 4 -4 of Fig.2 2; 7

Fig. 5 is a fragmentary, vertical section taken along the longitudinal axis of a fluid holder formingga' part of an alternative embodiment" of the invention, and

Fig. 6 is a vertical sectiontaken along line 6 6 of Fig 5. I v

Referring now to Fig. 1, a filamenta'ry insulated-con ductor 10, such as 'copperwiife -11 ('Figj'ii) covered" with a sheath 12 ofplastic insulatiomfis continuously advanced lo'ng'itudirially bya capstan 15' in the direction "indicated by the arrow from' a plastics- 'extrude'rfnot shown) in which the sheath'ofplastic' insulationis 'applied-.- The; capstan i5 is rotated continuously from a-drive sl'iaft 16 driven 'byan electric motor 18.

Positioned between the plastics extruder (not shown) and the-capstan 15 'is'an applicator 20" for applying a helical-stripe of a coloring'fiuid, such" as'ink or--paint,to the exteriorsurface'ofthesheath 12. The applicator-20' includes aspin'dle 21 (Figs: 1 and 2') having "a central,- longitudinallyextending bore 25 through which the insul ated' conductor It) isadvanced' longitudinally in coaxial relation therewith; The-spindle 21 is rotatably journaled at its ends in ball bearings 27 'and28 mounted in axially aligned annular recesses 30 and 31, respectively, adjoinin'g cir'cu'la-r apertures 33 and- 34, respectively, formed in the vertical: wallsof a housing 35. Mounted on-the in termediate por tionof' the outer periphery of the spindle 21 and keyed thereto for rotation-'therewitli-is a 'belt sprocket' ttl'jwhich is-operative'lyconnected to the-drive sha'ft 16'through a positive belt 42'an'da belt-sprocket 43:

The right' hand-end of the spindle 2'1, as viewed in .Fi'gJ'Z, is provided 'witha flange 50f to -which'issecured fixedly; but removably, one' 'enfd ofa 'strip'eappli'cator 55.

The stripe'applicato'r 55* is designed to' surround the advancing insulated 7 conductor 10 coaxially, and is made" preferably froma relatively rigid, rod-'like material, suclr as'hard'steehwi're,or-the like.- The stripe applicator 55 is formed: into 'a hellx having' a predetermined helix angle; the internal diameter ofwhich helix is somewhat greate'r than 'the outer diameter of the sheath 12.

The stripe applicator 55 is received coaxially within -a longitudinallyextending, cylindrical chamber 57 formed in the'left hand end, as viewed in Fig. 2, of a fluid' holder 60.: Theright hand end of the chamber 57 communicates with a tapered counterbore 61yand1a cylindrical chamber 62 having: a diameter substantially greater than the diameter of the chamber 57-. The right hand end of the chamber 62 is'closed, except for a. circular aperture 64,

through which the longitudinally advancing insulated conducto'r ltj'emerge's. Assliown in Fig. 2, the diameter of the 'ch'amber57' is' slightly larger than "theexternal diami eter of the stripe applicator" 55 positioned therein.

A bore 70 extends through the wall of the stationary member '60 -"and cQmmHnicates' tangentially with the chamber 57. I The bore 70 is conected' by a pipe 71w the dis'charge -portof an "adjustable, positivefdisp'lacement,-rotary pump*-72 connected to the-drive shaft 16" through-gears 74 'and 75. The drive shaft 16"is de-- signed to operate the pump 72 continuously to' deliver a coloring fiuid-,-such as a colored marking -ink 77, from a reservoir 73 to the'chamber' 57' in the fluid holder'otl at apredetermined constant flow rate. The reservoir'78" is connected to the intake port'on the pump 72 by means of. a pipe 80; A pipe '83 extends radially through the.

wall ofthe fluid holder 60 and communicateswith the bottom of the chamber 62 formed therein. The pipe 83 is designed to return the marking ink 77 to the reservoir 78 as fast as it collects in the chamber 62.

Operation applicator 55 and the chamber 57 in the fluid holder 6%,

and emerges through the circular aperture 64.

The spindle 21 is rotatably driven at a constant predetermined speed to rotate the stripe applicator 55 continuously about its longitudinal axis within the chamber 57. The rotational speed of the spindle 21, by design, is such that the advance of the helix of the stripe applicator 55 is synchronized at or near the linear speed of the insulated conductor 10.

In addition to driving the capstan and the spindle 21, the drive shaft 16 operates the pump 72 continuously at a predetermined rate, whereby the pump delivers a constant predetermined flow of the marking ink 77 to the chamber 57 through the bore 70.

The continuously rotating stripe applicator 55 picks up the marking ink 77 and whirls it outwardly against and completely around the wall of the chamber 57 to form an advancing cylindrical shell 85 of marking ink inside the wall of the chamber. The thickness of the cylindrical shell 85 of the marking ink 77 may be varied by adjusting the rate of flow at which the marking ink is supplied to the chamber 57 by the pump 72.

The frictional retardation of the advance of the cylindrical shell 85 of marking ink 77 along the wall of the chamber 57 cooperating with the continuously rotating, stripe applicator 55 creates a continuous helical wave 86 on the free surface of the cylindrical shell 85. The helical wave 86 advances continuously from left to right, as viewed in Fig 2, at or near the speed of the longitudinally advancing insulated conductor 10. The height of the crest of the helical wave 86 measured radially from the wall of the chamber 57, is made by adjustment of the fluid supply flow such that the crest just touches the exterior surface of the sheath 12 of plastic insulation on the insulated conductor 10, whereby a continuous helical stripe 90 of the marking ink 77 is applied thereto.

Assuming that the height of the crest of the traveling helical wave 86 of the marking ink 77 remains constant, the width of the stripe 90 applied to the exterior surface of the sheath of plastic insulation 12 is a minimum when the speed of advance of the traveling helical wave and the linear speed of the insulated wire are precisely matched. To increase the width of the helical stripe 90, it is necessary to change the linear speed of the insulated conductor 10 or the rotational speed of the rotating spindle 21 slightly to cause the speed of advance of the traveling wave 86 of marking ink 77 to vary slightly from the synchronous speed.

The enlarged chamber 62' is designed to catch the excess marking ink 77 after it has advanced through the chamber 57 so that the ink may be carried back to the reservoir 78 through the pipe 83. The surface tension properties of the marking ink 77 and its adherence to the wall of the chamber 57 are such as to prevent it from dripping on the insulated conductor 10 as the conductor passes through the chamber 57, and the ink flows into and down the wall of the chamber 62 to the bottom thereof.

Alternative embodiment Illustrated in Figs. 5 and 6 is an apparatus forming an alternative embodiment of the invention. This apparatus is similar in construction to the apparatus shown in Figs. 1 to 4, inclusive, except for the construction of the stripe applicator.

Referring now to Figs. 5 and 6, the apparatus includes a rotatably driven spindle 121, identical in construction to the spindle 21 and provided similarly with a flange at the right hand end thereof. Secured fixedly, but removably, to the flange 150 for rotation therewith is one end of a stripe applicator 155. The stripe applicator is made preferably from a relatively rigid, rodlike material, such as hard steel wire, or the like. The left hand portion of the stripe applicator 155, as viewed in Fig. 5, is formed into a helix having an internal diameter somewhat greater than the outer diameter of a sheath 112 of insulation on an insulated conductor 110.

The right hand end portion of the stripe applicator 155, instead of being helical as in the case with the stripe applicator 55, is formed into a semicircle, the plane of which is perpendicular to the longitudinal axis of the continuously advancing insulated conductor 110. Both the helical portion and the semicircular end portion of the stripe applicator 155 are concentric with respect to the longitudinal axis of the continuously advancing insulated conductor 110. The extremity of the semicircular end portion of the applicator 155 is provided with a nodule 156 which projects radially inwardly toward the exterior surface of the insulation 112 on the advancing insulated conductor 110, but is spaced slightly therefrom and does not contact the surface.

The unsupported portion of the applicator 155 is received coaxially within a longitudinally extending, cylindrical chamber 157 formed in the left hand end, as viewed in Fig. 5, of a fluid holder 160. The fluid holder 160 is identical in construction to the fluid holder 60 heretofore described, and is provided likewise with a tapered counterbore 161 and a cylindrical chamber 162 having a diameter substantially greater than that of the chamber 157. The right hand end of the chamber 162 is closed, except for a small circular aperture 164 through which the advancing insulated conductor 110 emerges.

As in the first-mentioned embodiment of the invention, the diameter of the chamber 157 is slightly larger than the exterior diameter of the stripe applicator 155 positioned coaxially therein. A tangentially positioned bore and an outlet pipe 183 communicate. with the chamber 157 and the chamber 162, respectively, to provide means for circulating a predetermined flow of a marking ink 177, in a manner identical to that described previously in relation to the first-mentioned embodiment of the invention.

Operation of alternative embodiment In the operation of this embodiment of the invention, the spindle 121 is rotated continuously at a predetermined speed to rotate the stripe applicator 155 about its longitudinal axis by drive means identical to that described in connection with the first-mentioned embodiment of the invention. Similarly a pump is operated continuously to deliver a constant predetermined flow of the marking ink 177 to the chamber 157 through the bore 170.

The continuously rotating stripe applicator 155 picks up the marking ink 177 as it is delivered through the tangentially oriented bore 170 and whirls it outwardly and completely around the wall of the chamber 157 to form an advancing cylindrical shell 185 of marking on the wall of the chamber. As in the first-mentioned embodiment of the invention, the thickness of the cylindrical shell 185 of marking ink 177 is adjustable by adjusting the rate of flow at which the marking ink is supplied to the chamber 157. The thickness of the cylindricalshell 1850f. marking ink. 177 mustbe suflicient to completely submerge. the nodule 156 without permitting the free surface of. the cylindrical shell 185 to. contact the exterior surface of theinsulation 112.

The nodule-156 moves in a circular path about the longitudinal axis of the advancing insulatingconductor 110;v and as it so moves it creates asmall bulge 186 which; projectsradiallyinward from the free surface of the cylindricalshell 185 of marking ink 177. This bulge 186 travels ina circular path about the advancing insulatedconductorllfl, and the height of its crest, measured radiallyfrom the wall ofthe chamber 157, is adjusted so that its crest just touches the. exterior surface of the insulation 112, whereby-a continuous helical stripe 190 of-the marking 'ink 177 is applied thereto. It will be understood that the bulge 1860f marking ink 177 does notadvance longitudinally along the bore 157, but remains in the plane of the rotating nodule 156 on the extremity of the applicator 155.

. The. marking ink 177 forming the cylindrical shell on the-wall of thechamber 157 flows continuously from left to'right, as viewed in Fig. 4, into the enlarged chamber- 162-where it is collected and recirculated through the pipe 183; The latter movementof the cylindrical shell 186 -.of marking ink 177 results from the impeller action of. the helical left hand portion of the stripe applicator 155, as vie-wed in Fig. 5. The helix angleof the stripe 190'may be adjusted by adjusting either the speed of rotation of the spindle 121,011- the linear speed of the continuously advancing conductor 110.

It will be understood that this invention is. not limited to the applicationqof helical stripesof ink.to insulated conductors. It is readily apparent that the invention may be; employed to apply stripes of ink or of other materials to various elongated articleshaving substantially circular cross sections, for example elongated rods, pipes and the like.

What is claimed is:

1. The method of applying indicia to the outer periphery of an elongated, generally cylindrical article, which comprises the steps of advancing such an article continuously in the direction of its length, forming a substantially cylindrical body of marking fluid concentrically about and having its free surface spaced from the ad vancing article, and producing a swell on the free surface of the cylindrical body of marking fluid immediately adjacent to the advancing article of such height that the crest thereof contacts the outer periphery of the article.

2. The method of applying a helical stripe to the outer periphery of an elongated, generally cylindrical article, which comprises the steps of advancing such an article continuously in the direction of its length at a predetermined linear speed, forming a substantially cylindrical body of a marking fluid concentrically about and having its free surface spaced from the advancing article, and propagating a continuous helical wave on the free surface of the cylindrical body of marking fluid immediately adjacent to the advancing article, which advances at a speed substantially equal to the linear speed of the article and is of a height such that the crest thereof contacts the outer periphery of the article.

3. The method of applying a helical stripe to an elongated, generally cylindrical article, which comprises the steps of advancing such an article continuously in the direction of its length, forming'a substantially cylindrical body of marking fluid concentrically about and having its free surface spaced from the advancing article, producing a bulge on the free surface of said body immediately adjacent to the advancing article of a height such that the crest thereof contacts the outer periphery of the continuously advancing article, and simultaneously causing the bulge to rotate in an orbital path about the advancing article whereby a helical stripe of the marking fluid is applied thereto.

6 4. Apparatus. for applyingindicia to the-outer periphery of an elongated, generally cylindricaliiarticle, which comprises a member provided .witha cylindricalchamber,

means for advancing such an article continuously through the chamber in substantially concentric alignment therewith, the diameter of the chamber being substantially greater than the outer diameter of the article, means for forming a cylindrical shell of marking fluid on the wall of the chamber with the free surface of'said shell of marking fluid spaced from the outer periphery of 'the'article, and means for producing a swell on the surface of'the shell of marking fluid of such height that the crest thereofcontacts the outer periphery of the article. I

5; Apparatus for applying a helical stripe; of marking fluid to the outer periphery of an. elongated generally cylindrical article, which comprisesa member'provide'd with a longitudinally extending cylindricalcha-m'ber,

means for advancing such an article continuously through the chamber in substantially concentric alignment therewith, thediameter, of. the chamber being substantially greater than the outerdiameter of the article, means'for forming a cylindrical shell 'of marking fluid on the Wall of the chamber with the free surface of said shell of marking fluid being spaced from the. outerperiphery of the article, and means for propagating a helical wave on the surface of the shell of marking fluid, said wave traveling in the direction of the advance of the article at a speed substantially equal to the linearspe'ed of the article. and having a height such'that the 'crest thereof contacts the outer periphery of the article;

6. Apparatus for applying a.helical stripe of marking fluid to. the outer periphery of an elongated generally cylindrical article, which comprises a member provided with a longitudinally. extending cylindrical chamber,

means for. advancing such an article continuously through.

the, chamber in substantially concentric alignment therewith and at a predetermined linear speed, the diameter of the chamber being substantially greater than the outer diameter of the article, means for supplying marking fluid to the interior of the chamber, a helical element mounted for rotation concentrically within the chamber between the Wall of the chamber and the outer periphery of the advancing article, and means for rotating the helical element at a predetermined speed whereby the marking fluid supplied to the chamber is formed into a cylindrical shell on the wall of the chamber. with the free surface of said shell spaced from the outer periphery of the article, said helical element being submerged in the cylindrical shell of marking fluid and propagating a helical wave on the free surface thereof which travels in the direction of the advance of the article at a speed substantially equal to the linear speed of the article and has a height such that the crest thereof'contacts the outer periphery of the article.

7. Apparatus for applying a helical stripe of marking fluid to the outer periphery of an elongated, generally cylindrical article, which comprises a body member provided With'a longitudinally extending cylindrical chamber, means for advancing such an article continuously through the chamber in substantially concentric alignment therewith and at a predetermined linear speed, the diameter of the chamber being substantially greater than the outer diameter of the article, means for supplying marking fluid to the interior of the chamber, a helically shaped, rod-like member mounted for rotation concentrically within the chamber between the wall of the chamber and the outer periphery of the advancing article, and means for rotating the rod-like member at a predetermined speed whereby the marking fluid supplied to the chamber is formed into a cylindrical shell on the wall of the chamber, said rod-like member being submerged in the cylindrical shell of marking fluid and propagating a helical wave on the surface thereof which travels in the direction of the advance of the article at a speed substantially equal to the linear speed of the article and has a height such that the crest thereof contacts the outer periphery of the article.

8. Apparatus for applying a helical stripe of marking fluid to the outer periphery of an elongated, generally cylindrical article, which comprises a member provided With a longitudinally extending cylindrical chamber, means for advancing such an article continuously through the chamber in substantially concentric alignment therewith, the diameter of the chamber being substantially greater than the outer diameter of the article, means for forming a cylindrical shell of marking fluid on the wall of the chamber, the free surface of said shell of marking fluid being spaced from the outer periphery of the article, and means for producing a bulge on the surface of the shell of marking fluid, which travels in an orbital path in a plane substantially transverse to the longitudinal axis of the advancing article and is of a height such that the crest thereof contacts the outer periphery of the article.

9. Apparatus for applying a helical stripe of marking fluid to the outer periphery of an elongated, generally cylindrical article, which comprises a member provided with a longitudinally extending cylindrical chamber, means for advancing such an article continuously through the chamber in substantially concentric alignment therewith, the diameter of the chamber being substantially greater than the outer diameter of the article, means for forming a cylindrical shell of marking fluid on the wall of the chamber, the free surface of said shell of marking fluid being spaced from the outer periphery of the article, and a continuously rotating agitator provided with an inwardly projecting protuberance submerged in the shell of marking fluid for producing a bulge on the surface of the shell of marking fluid, said bulge rotating in an orbital path in a plane substantially transverse to the longitudinal axis of the advancing article and having a height such that the crest thereof contacts the outer periphery of the article.

10. Apparatus for applying a helical stripe of marking fluid to the outer periphery of an elongated generally cylindrical article, which comprises a member provided with a longitudinally extending cylindrical chamber, means for advancing such an article continuously through the chamber in substantially concentric alignment therewith and at a predetermined linear speed, the diameter of the chamber being substantially greater than the outer diameter of the the article, an agitator formed from a stiff rod-like material and provided with a helically-shaped initial portion and a semicircular end portion, said agitator being mounted for rotation concentrically within the chamber between the Wall thereof and the outer periphery of the advancing article, means for rotating the agitator continuously at a predetermined speed, means for supplying marking fluid to the interior of the chamber at a predetermined rate of flow, whereby the marking fluid is formed through centrifugal force into a substantially cylindrical shell having a depth sufficient to submerge the agitator and having its free surface spaced from the outer periphery of the article, and an inwardly projecting protuberance formed on the semicircular end portion of the agitator, said protuberance being completely submerged in the shell of marking fluid and designed to produce on the free surface of said shell a bulge of a height such that the crest thereof contacts the outer periphery of the advancing article, which rotates in an orbital path about the article so as to apply a helical stripe of marking fluid thereto.

References Cited in the file of this patent UNITED STATES PATENTS 

1. THE METHOD OF APPLYING INDICIA TO THE OUTER PERIPHERY OF AN ELONGATED, GENERALLY CYLINDRICAL ARTICLE, WHICH COMPRISES THE STEPS OF ADVANCING SUCH AN ARTICLE, WHICH TINUOUSLY IN THE DIRECTION OF ITS LENGTH, FORMING A SUBSTANTIALLY CYLINDRICAL BODY OF MARKING FLUID CONCENTRICALLY ABOUT AND HAVING ITS FREE SURFACE SPACED FROM THE ADVANCING ARTICLE, AND PRODUCING A SWELL ON THE FREE SURFACE OF THE CYLINDRICAL BODY OF MARKING, FLUID IMMEDIATELY ADJACENT TO THE ADVANCING ARTICLE OF SUCH HEIGHT THAT THE CREST THEREOF CONTACTS THE OUTER PERIPHERY OF THE ARTICLE. 